Dynamic facial skin thermography in glaucoma. Technique and practical application

Aim: To develop a high-sensitivity method of localized dynamic thermographic evaluation of the face skin surface and to assess the correlation between thermal parameters and current indicators of glaucoma-associated damage.

Methods: 69 glaucoma patients (138 eyes) and 52 healthy volunteers (104 eyes) were enlisted in the study. All subjects underwent dynamic infrared thermography following an algorithm developed by our research group and conducted in a special room with optimal parameters of the environment. Cold test applicator was applied to the area of the inferior margin of the zygomatic bone for 20 s, then infrared images of this area were captured every 20 s for the following 5 min. Temperature recovery curve for all patients was plotted based on the acquired data. The sum of received curves' deviations from a theoretical “ideal" temperature recovery curve constituted the cumulative temperature difference coefficient - 1ДТ.

Results: Mean cumulative temperature difference 8.32+4.65° for glaucoma patients and 6.09+3.54° for healthy volunteers. Difference between groups was statistically significant (p<0.05). A statistically significant correlation was also observed between glaucoma stage and 1ДТ: its value decreased with glaucoma progression. Additionally, topical antiglaucoma therapy, as well as its absence, influenced 1ДТ. Use of prostaglandin analogs, beta-adrenergic blockers, carbonic anhydrase inhibitors caused the increase of 1ДТ to a level corresponding to an earlier glaucoma stage.

Conclusion: Data acquired in this study indicate that extraocular dynamic thermography of facial skin surface may be a reliable method of evaluating pathologic microvascular changes characteristic to glaucoma.

1. Emre M., Orgul S., Gugleta K., Flammer J. Ocular blood flow alteration in glaucoma is related to systemic vascular dysregulation. Br J Ophthalmol. 2004; 88(5):662-666.

2. Fuchsjager-Mayrl G., Wally B., Georgopoulos M., Rainer G. et al. Ocular blood flow and systemic blood pressure in patients with primary open-angle glaucoma and ocular hypertension. Invest Ophthalmol Vis Sci. 2004; 45(3):834-839.

3. Broadway D.C., Drance S.M. Glaucoma and vasospasm. Br J Ophthalmol. 1998; 82(8):862-870.

4. Gugleta K., Orgul S., Flammer J. Is corneal temperature correlated with blood-flow velocity in the ophthalmic artery? Curr Eye Res. 1999; 19(6):496-501.

5. Morgan P.B., Smyth J.V., Ullo A.B., Efron N. Ocular temperature in carotid artery stenosis. Optom Vis Sci. 1999; 76(12):850-854.

6. Horn F.K., Michelson G., Schnitzler E., Mardin C.Y. et al. Visual evoked potentials of the blue-sensitive pathway under cold provocation in normals and glaucomas. J Glaucoma. 2006; 15(1):17-22.

7. Bouvier P., Berrod J.P., Garniche J., Schmidt C. et al. Ocular vasospasm in cold provocation test and primary vascular acrosyndrome. JFr Ophtalmol. 1995; 18(2):151-153.

8. Arutyunyan L.L. The relationship between structural functional parameters and scleral collagen cross-linking level in glaucoma eyes. Natsionalniy zhurnal glaucoma. 2015; 14(4):5-12. (In Russ.).

9. Fuchsjager-Mayrl G., Georgopoulos M., Hommer A., Weigert G. et al. Effect of dorzolamide and timolol on ocular pressure: blood flow relationship in patients with primary open-angle glaucoma and ocular hypertension. Invest Ophthalmol Vis Sci. 2010; 51(3):1289-1296. doi: 10.1167/iovs.09-3827